Layout modification method for exposure manufacturing process

ABSTRACT

A layout modification method for fabricating a semiconductor device is provided. The layout modification method includes calculating uniformity of critical dimensions of first and second portions in a patterned layer by using a layout for an exposure manufacturing process to produce the semiconductor device. A width of the first and second portions equals a penumbra size of the exposure manufacturing process. The penumbra size is utilized to indicate which area of the patterned layer is affected by light leakage exposure from another exposure manufacturing process. The layout modification method further includes compensating non-uniformity of the first and second portions of the patterned layer according to the uniformity of critical dimensions to generate a modified layout. The first portion is divided into a plurality of first sub-portions. The second portion is divided into a plurality of second sub-portions. Each second sub-portion is surrounded by two of the first sub-portions.

CROSS REFERENCE

This application is a Continuation of U.S. application Ser. No.16/933,127, filed on Jul. 20, 2020, which is a Continuation of U.S.application Ser. No. 16/522,825, filed on Jul. 26, 2019, now U.S. Pat.No. 10,720,419 (issued on Jul. 21, 2020), which is a Continuation ofU.S. application Ser. No. 15/797,842, filed on Oct. 30, 2017, now U.S.Pat. No. 10,366,973 (issued on Jul. 30, 2019), the entirety of which areincorporated by reference herein.

BACKGROUND

Integrated circuits (ICs) have become increasingly important.Applications using ICs, such as cell phones, smartphones, tablets,laptops, notebook computers, PDAs, wireless email terminals, MP3 audioand video players, portable wireless web browsers and the like, are usedby millions of people. Integrated circuits increasingly include powerfuland efficient on-board data storage and logic circuitry for signalcontrol and processing. In the course of IC evolution, functionaldensity (i.e., the number of interconnected devices per chip area) hasgenerally increased while geometric size (i.e., the smallest component(or line) that can be created using a fabrication process) hasdecreased. This scaling-down process generally provides benefits byincreasing production efficiency and lowering the associated costs.

Various semiconductor processes have been used for manufacturingintegrated circuits, and different pattern densities might be requiredfor the semiconductor processes (especially the exposure manufacturingprocesses). Although existing exposure techniques have been generallyadequate for their intended purposes, they have not been entirelysatisfactory in when it comes to uniformly assessing exposure issues foradvanced technology nodes.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It shouldbe noted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1A is a simplified block diagram of an embodiment of an integratedcircuit (IC) manufacturing system and an associated IC manufacturingflow.

FIG. 1B is a more detailed block diagram of the exposure system shown inFIG. 1 according to various aspects of the present disclosure.

FIG. 2A is a schematic diagram of a semiconductor device for executing aseries of exposure manufacturing process, in accordance with someembodiments.

FIG. 2B is a schematic diagram of a semiconductor device with a layout,in accordance with some embodiments.

FIG. 2C is a schematic diagram of a semiconductor device illustratingthe patterned layer, in accordance with some embodiments.

FIG. 2D is a schematic diagram of a semiconductor device illustratingthe patterned layer, in accordance with some embodiments.

FIG. 3 is a schematic diagram illustrating the relation betweenuniformity of critical dimensions and different steps of compensation,in accordance with some embodiments.

FIG. 4 is a flow chart illustrating the layout modification method of anexposure manufacturing process for fabricating an integrated circuit(IC), in accordance with some embodiments.

Corresponding numerals and symbols in the different figures generallyrefer to corresponding parts unless otherwise indicated. The figures aredrawn to clearly illustrate the relevant aspects of the embodiments andare not necessarily drawn to scale.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in some various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween some various embodiments and/or configurations discussed.

Furthermore, spatially relative terms, such as “beneath,” “below,”“lower,” “above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Some embodiments of the disclosure are described. Additional operationscan be provided before, during, and/or after the stages described inthese embodiments. Some of the stages that are described can be replacedor eliminated for different embodiments. Additional features can beadded to the semiconductor device. Some of the features described belowcan be replaced or eliminated for different embodiments. Although someembodiments are discussed with operations performed in a particularorder, these operations may be performed in another logical order.

FIG. 1A is a simplified block diagram of an embodiment of an integratedcircuit (IC) manufacturing system 100 and an associated IC manufacturingflow, which may benefit from various aspects of the present disclosure.The IC manufacturing system 100 includes a plurality of entities, suchas a design house 102, a mask house 110, and an IC manufacturer 120(i.e., a fab), that interact with one another in the design,development, and manufacturing cycles and/or services related tomanufacturing an integrated circuit (IC) 130. The IC 130 may include aplurality of semiconductor devices.

In integrated circuit (IC) design, a variety of functions are integratedinto one chip, and an application specific integrated circuit (ASIC) orsystem on a chip (SOC) cell based design is often used. In thisapproach, a library of known functions is provided, and after thefunctional design of the device is specified by choosing and connectingthese standard functions, and proper operation of the resulting circuitis verified using electron IC design layout automation (EDA) tools, thelibrary elements are mapped on to predefined layout cells, which containprefigured elements such as transistors. The cells are chosen with theparticular semiconductor process nodes and parameters in mind and createa process parameterized physical representation of the design. Thedesign flow continues from that point by performing placement androuting of the local and global connections needed to form the completeddesign using the standard cells.

After design rule checks, design rule verification, timing analysis,critical path analysis, static and dynamic power analysis, and finalmodifications to the design, a tape out process is performed to producephotomask generation data. This photomask generation (PG) data is thenused to create the optical masks used to fabricate the semiconductordevice in a photolithographic process at a wafer fabrication facility(FAB). In the tape out process, the database file of the IC is convertedinto a Graphic Database System (GDS) file (e.g., a GDS file or a GDSIIfile). The GDS file is then used to make various layers of masks forintegrated circuit manufacturing. Specifically, the GDS file became theindustry's standard format for transfer of IC layout data between designtools of different vendors.

The plurality of entities are connected by a communications network,which may be a single network or a variety of different networks, suchas an intranet and the Internet, and may include wired and/or wirelesscommunication channels. Each entity may interact with other entities andmay provide services to and/or receive services from the other entities.One or more of the design house 102, the mask house 110, and the ICmanufacturer 120 may be owned by a single larger company, and may evencoexist in a common facility and use common resources.

The design house (or design team) 102 generates an IC design layout 104.In some embodiments, the IC design layout 104 includes processing datawhich are used in semiconductor processes for manufacturing the IC 130.The processing data could include at least one design parameter and atleast one exposure parameter of an exposure manufacturing process of athin film of a semiconductor device of the IC 130. For example, thedesign parameter could be pattern-density (PD).

The mask house 110 uses the IC design layout to manufacture one or moremasks to be used for fabricating various layers of the IC 130. The maskhouse 110 performs parameter preparation 112, and other suitable tasks.The parameter preparation 112 translates the IC design layout 104 into aform that can be physically written by a mask writer. The mask house 110then fabricates a plurality of masks that are used for patterning asubstrate (e.g., a wafer).

The IC design layout 104 may further include various geometricalpatterns designed for the IC 130. The geometrical patterns correspond topatterns of metal, oxide, or semiconductor layers that make up thevarious components of the IC 130 to be fabricated. The various layerscombine to form various IC features. For example, a portion of the ICdesign layout 104 includes various IC features, such as active regions,gate electrodes, sources and drains, metal lines or vias of aninterlayer interconnection, and openings for bonding pads, to be formedin a semiconductor substrate (such as a silicon wafer) and variousmaterial layers disposed on the semiconductor substrate. The designhouse 102 implements a proper design procedure to form the IC designlayout 104. The design procedure may include logic design, physicaldesign, and/or place and route.

The mask house 110 is utilized to determine processing parametersincluding an adjusting parameter and/or a compensation index. Thedetermined processing parameters are utilized to generate a mask, andthe mask is transmitted to the FAB 120. Therefore, the exposuremanufacturing process is performed on the wafer 122 in the FAB 120according to the processing parameters which were determined by the maskhouse 110.

The mask house 110 includes a parameter preparation 112, and theparameter preparation 112 receives the IC design layout 104 from thedesign house 102 to generate processing parameters for manufacturing thesemiconductor devices on the wafer 122. Specifically, the adjustingparameter is utilized for modifying the layout of the semiconductordevice. In some embodiments, the adjusting parameter is a Mask ErrorEnhancement Factor (MEEF) which is utilized for optical proximitycorrection of the exposure manufacturing process of the semiconductordevice. The compensation index is utilized for multiplying thecompensation amount to generate a modified layout. The compensationindex is related to the area of the patterned layer.

The parameter preparation 112 may include additional modules, such asoptical proximity correction (OPC), mask rule checker, lithographyprocess checker, and other resolution enhancement techniques (RET),which are not shown here. As lithography exposure using deep ultravioletlight (such as 193 nm) approaches its resolution limits, varioustechniques are devised for extending the usable life of the existinglithography tools. One of the techniques is mandrel spacer patterning.In this technique, a mandrel pattern is formed using an exposure, and aspacer pattern is formed on sidewalls of the mandrel pattern. Then, themandrel pattern is removed and the spacer pattern is used for furtherpatterning steps in order to form a final pattern. The pitch of thespacer pattern is reduced to only half of that of the mandrel pattern,thereby increasing the resolution of the patterning process.

In some embodiments, the mask house 110 may further include lithographyprocess checking (LPC) that simulates processing that will beimplemented by the FAB 120 to fabricate the IC 130. The LPC may simulatethis processing based on the IC design layout 104 to create a simulatedmanufactured device, such as the IC 130. The processing parameters inLPC simulation may include parameters associated with various processesof the IC manufacturing cycle, parameters associated with tools used formanufacturing the IC, and/or other aspects of the manufacturing process.By way of example, LPC may take into account various factors, such asaerial image contrast, depth of focus (“DOF”), mask error enhancementfactor (“MEEF”), other suitable factors, or combinations thereof. Thesimulated processing (e.g., implemented by the LPC) can be used toprovide for the generation of a process-aware rule table (e.g., for SRAFinsertions). Thus, an SRAF rule table may be generated for the IC designlayout 104, with consideration of the processing conditions of the maskhouse 110.

After parameter preparation 112 in the mask house 110 modifies the ICdesign layout 104, a modified layout or a group of modified layouts arefabricated. For example, an electron-beam (e-beam) or a mechanism ofmultiple e-beams is used to form a pattern on a mask (photomask orreticle) based on the modified layout. In addition, the mask can beformed based on the modified layout in various technologies. Forexample, the mask may be formed using binary technology to includeopaque regions and transparent regions. A radiation beam (such as anultraviolet (UV) beam), used to expose the image sensitive materiallayer (e.g., photoresist) coated on a wafer, is blocked by the opaqueregion and transmits through the transparent regions. In one example, abinary mask includes a transparent substrate (e.g., fused quartz) and anopaque material (e.g., chromium) coated in the opaque regions of themask. In another example, the mask is formed using a phase shifttechnology. In a phase shift mask (PSM), various features in the patternformed on the mask are configured to have proper phase difference toenhance the resolution and imaging quality.

The IC manufacturer 120, such as a semiconductor foundry, uses the maskgenerated by the mask house 110 to fabricate the IC 130. The ICmanufacturer 120 is an IC fabrication business that can include a myriadof manufacturing facilities for the fabrication of a variety ofdifferent IC products. For example, there may be a first manufacturingfacility for the front end fabrication of IC products (i.e.,front-end-of-line (FEOL) fabrication), while a second manufacturingfacility may provide the back end fabrication for the interconnectionand packaging of the IC products (i.e., back-end-of-line (BEOL)fabrication), and a third manufacturing facility may provide otherservices for the foundry business.

In the present embodiment, a wafer 122 is fabricated using a mask toform the IC 130. The semiconductor wafer includes a silicon substrate oranother proper substrate having material layers formed thereon. Otherproper substrate materials include another suitable elementarysemiconductor, such as diamond or germanium; a suitable compoundsemiconductor, such as silicon carbide, indium arsenide, or indiumphosphide; or a suitable alloy semiconductor, such as silicon germaniumcarbide, gallium arsenic phosphide, or gallium indium phosphide. Thewafer 122 may further include various doped regions, dielectricfeatures, and multilevel interconnects (formed at subsequentmanufacturing steps).

FIG. 1B is a more detailed block diagram of the mask house 110 shown inFIG. 1A according to various aspects of the present disclosure. One ormore of the tools and systems and operations described with respect toFIG. 4 is realized in some embodiments by the mask house 110 of FIG. 1B.The exposure system 100 includes a processor 1101, a memory 1102, anetwork interface (I/F) 1103, a display 1104, an input/output (I/O)device 1105, and one or more hardware components 1106 communicativelycoupled via a bus 1107 or another interconnection communicationmechanism.

The processor 1101 may include a digital signal processor (DSP), amicrocontroller (MCU), a central-processing unit (CPU) or a plurality ofparallel processors relating the parallel processing environment toimplement the operating system (OS), firmware, driver and/or otherapplications of the mask house 110.

The memory 1102 includes, in some embodiments, a random access memory(RAM) or another dynamic storage device or read only memory (ROM) orother static storage devices, coupled to the bus 1107 for storing dataand/or instructions to be executed by the processor 1101. The memory1102 is also used, in some embodiments, for storing temporary variablesor other intermediate information during the execution of instructionsto be executed by the processor 1101.

The communication module 1103 is operable to communicate informationsuch as IC design layout files with the other components in the ICmanufacturing system 100, such as design house 102. Examples ofcommunication modules may include Ethernet cards, 802.11 WiFi devices,cellular data radios, and/or other suitable devices known in the art.

The display 1104 is utilized to display the processing data andprocessing parameter the IC 130. The display 1104 can be aliquid-crystal panel or a touch display panel. The I/O device 1105includes an input device, an output device and/or a combinedinput/output device for enabling user interaction with the mask house110. An input device includes, for example, a keyboard, keypad, mouse,trackball, trackpad, and/or cursor direction keys for communicatinginformation and commands to the processor 1101. An output deviceincludes, for example, a display, a printer, a voice synthesizer, etc.for communicating information to the user.

FIG. 2A is a schematic diagram of a semiconductor device 200 forexecuting a series of exposure manufacturing processes, in accordancewith some embodiments. The layout of the semiconductor device 200 couldbe divided into a plurality of regions 200A˜200I. Each of the regions200A˜200I is formed in a polygon shape. In some embodiments, each of theregions 200A˜200I is formed in a rectangle shape. The exposuremanufacturing processes are executed for each of the regions 200A˜200Isequentially. For example, the region 200A is exposed with a lightsource, then the region 200B is exposed by the light source, then theregion 200C is exposed by the light source and so on.

Specifically, a pellicle (i.e., a transparent thin film) is utilized tocover the regions 200A˜200I in order to prevent the semiconductor device200 from being damaged by particles. However, a portion of light fromthe light source will be reflected by the pellicle, especially theout-of-band light which is transmitted by the light source but notutilized for the exposure manufacturing process. The reflected lightmight result in uniformity for the exposure manufacturing process.

After the regions 200A˜200I are covered by the pellicle, the exposuremanufacturing process may be executed for each of the regions 200A˜200Isequentially. Specifically, a plurality of blades are utilized to exposethe light for a specific region and block the light for other regions(which means other regions will not be exposed by the light). Forexample, when the exposure manufacturing process is performed for theregion 200B, several blades are arranged along the four edges of theregion 200B to block and obstruct the light transmitted from the lightsource. The above blades may not completely block the light during theexposure manufacturing process, and the light leakage will be generatedaccordingly and affect other surrounding regions. For example, the lightleakage of the region 200B will affect its surrounding regions 200A,200C and 200E. Therefore, regarding the regions 200A, 200C and 200E,their edge areas adjacent to the region 200B will suffer non-uniformity,which is caused by the pellicle and the light leakage from the region200B.

FIG. 2B is a schematic diagram of a region 200E of the semiconductordevice 200, in accordance with some embodiments. In some embodiments,the region 200E may be divided into several portions. As shown in FIG.2B, the region 200E is divided into a portion R1, a portion R2 and aportion R3. The portion R2 is adjacent to the portion R1, and theportion R3 is adjacent to the portion R2. The portion R2 includes fourportions R2-1, R2-2, R2-3 and R2-4. The portion R3 includes fourportions R3-1, R3-2, R3-3 and R3-4.

In the embodiment of FIG. 2B, the shape of the region 200E is a polygon.More specifically, the shape of the region 200E is a rectangle. Theportion R1 is the central portion of the rectangle, the portions R2-1,R2-2, R2-3 and R2-4 are the edge portions of the rectangle, and theportions R3-1, R3-2, R3-3 and R3-4 are the corner portions of therectangle. As shown in FIG. 2B, each of the portions R3-1, R3-2, R3-3and R3-4 is a square, and the length of the square is L1. Each of theportions R2-1 and R2-3 is a rectangle, width of the rectangle is L2, andlength of the rectangle is L1. Each of the portions R2-2 and R2-4 is arectangle, width of the rectangle is L2, and length of the rectangle isL3. The portion R1 is a rectangle with length L3 and width L1. Morespecifically, L3 is greater than L2, and L2 is greater than L1. In otherembodiments, the portion R1 is a square with length of L1. The portionsR2-1, R2-2, R2-3 and R2-4 are rectangles which are identical with eachother.

In some embodiments, the portions R2-1, R2-2, R2-3 and R2-4 are penumbraareas which are affected by the light leakage caused by exposuremanufacturing processes of other surrounding regions 200A˜200D and200F˜200I of the region 200E. More specifically, the portion R2-1 isaffected by the light leakage caused by the exposure manufacturingprocess of the region 200B, the region R2-2 is affected by the lightleakage caused by the exposure manufacturing process of the region 200F,the region R2-3 is affected by the region 200H, and the region R2-4 isaffected by the light leakage caused by the exposure manufacturingprocess of the region 200D.

In other words, the width L2 of each of the portions R2-1, R2-2, R2-3and R2-4 is equal to the penumbra size. The penumbra size is utilized toindicate which area of the patterned layer is affected by light leakagefrom another exposure manufacturing process. Furthermore, the penumbrasize can be calculated and simulated according to the category of lightsource, the intensity of the light source, the material of the blades,the distance between the light source and the blade, and the distancebetween the blade and the semiconductor device 200.

In addition, the portions R3-1, R3-2, R3-3 and R3-4 are the cornerportions of the rectangle. More specifically, the portion R3-1 isaffected by the light leakage caused by the exposure manufacturingprocess of the surrounding regions 200B, 200C and 200F of the region200E. The portion R3-2 is affected by the light leakage caused by theexposure manufacturing process of the surrounding regions 200F, 200H and200I of the region 200E. The portion R3-3 is affected by the lightleakage caused by the exposure manufacturing process of the surroundingregions 200D, 200G and 200H of the region 200E. The portion R3-4 isaffected by the light leakage caused by the exposure manufacturingprocess of the surrounding regions 200A, 200B and 200D of the region200E.

FIG. 2C is a schematic diagram of a modified layout of a semiconductordevice illustrating the patterned layer after compensation, inaccordance with some embodiments, along the cross section CS1 of theFIG. 2B. In some embodiments, the semiconductor device 200 includes twopatterned layers PL1 and PL2. The patterned layer PL2 is formed abovethe patterned layer PL1, the patterned layer PL1 can be formed above thewafer 122. For example, the patterned layer PL1 is a metal layer, andthe patterned layer PL2 includes a plurality of absorbers.

Each of the absorbers of the patterned layer PL2 is designed to have thesame width and the distance between any two of the adjacent absorbers(also known as the pitch) is designed to be the same. The criticaldimension (CD) can be determined by measuring the width or the pitch ofthe absorbers of the patterned layer PL2. However, because of theeffects of the light leakage and reflection in the penumbra area, thewidths of the absorbers on the penumbra area will be different from thewidths of the absorbers which are not on the penumbra area.

For example, the widths of the absorbers on the portion R2 are largerthan the widths of the absorbers on the portion R1 by 1 nm. In otherwords, the pitches of the absorbers on the portion R2 are less than thepitches of the absorbers on the portion R1 by 1 nm. Accordingly, avariety amount (ΔCD) of 1 nm could be measured or simulated in order toevaluate the uniformity of the CD in the regions R1, R2 and R3 for theregion 200E of the semiconductor device 200. Therefore, the uniformityof the patterned layer PL2 deteriorates, and a layout modificationmethod is needed to compensate for the non-uniformity.

In some embodiments, an adjusting parameter for modifying the layout ofthe semiconductor device 200 could be retrieved from the mask house 110by the processor 1101. In some embodiments, the adjusting parameter is aMask Error Enhancement Factor (MEEF) which is utilized for opticalproximity correction of the exposure manufacturing process of thesemiconductor device 200.

Afterwards, the processor 1101 determines a compensation amount (CA)based on the adjusting parameter and the uniformity of CD, andcompensates the CD of the second portion of the patterned layer byutilizing the compensation amount to generate a modified layout.Specifically, the compensation amount is determined by dividing varietyamount (ΔCD) (i.e., the uniformity of CD) by the adjusting parameter,which is illustrated as the equation (1).

Compensation Amount (CA)=ΔCD÷MEEF  (1)

For example, when the variety amount (ΔCD) is 1 nm which represents thedegree of the uniformity of CD and the MEEF of 2 is provided, the CAwill be 0.5 nm by the calculation of the equation (1).

In some embodiments, the CD of the portion R2 of the patterned layer iscompensated by increasing a pattern width of the portion R2 ordecreasing a pattern pitch of the portion R2 with the compensationamount which is multiplied by a first compensation index (C1). The firstcompensation index C1 is a positive value within a range of 0.5˜2. Thefirst compensation index C1 is related to the parameters of the exposuremanufacturing process and the position within the layout. For example,the first compensation index C1 is 1. The above compensation could beillustrated by the following equations (2) and (3).

W2=W1+(CA×C1)  (2)

P2=P1−(CA×C1)  (3)

In some embodiments, C1 is 1, CA is 0.5 nm, width W1 is 40 nm, and pitchP1 is 80 nm. By utilizing the equations (1)˜(3), width W2 will be 40.5nm, and pitch P2 will be 79.5 nm. As shown in the modified layout ofFIG. 2C, the width W2 in the portion R2 is larger than the width W1 inthe portion R1. The difference of 0.5 nm is determined by thecompensation amount CA and the first compensation index C1 to compensatefor the non-uniformity caused during the exposure manufacturing process.Due to the compensation, the non-uniformity between the portions R1 andR2 of the modified layout could be decreased.

FIG. 2D is a schematic diagram of a modified layout of a semiconductordevice 200 illustrating the patterned layer after compensation, inaccordance with some embodiments. In some embodiments, the CD of theportion R3 of the patterned layer is compensated by increasing a patternwidth of the portion R3 or decreasing a pattern pitch of the portion R3with the compensation amount which is multiplied by a secondcompensation index C2. The second compensation index C2 is greater thanthe first compensation index C1.

The second compensation index C2 is a positive value within a range of2˜5. The second compensation index C2 is related to the parameters ofthe exposure manufacturing process and the position within the layout.For example, the second compensation index C2 is 3. The abovecompensation could be illustrated by the following equations (4) and(5).

W3=W1+(CA×C2)  (4)

P3=P1−(CA×C2)  (5)

For example, C2 is 3, CA is 0.5 nm, W1 is 40 nm, and pitch P1 is 80 nm.By utilizing the equations (1)˜(5), width W3 will be 41.5 nm, and pitchP3 will be 78.5 nm. As shown in the modified layout of FIG. 2D, thewidth W3 in the portion R3 is larger than the width W1 in the portionR1. The difference of 1.5 nm is determined by the CA and C2 tocompensate for the non-uniformity caused during the exposuremanufacturing process. Due to the compensation, the non-uniformitybetween the portions R1 and R3 could be decreased.

Because the portion R3 is the corner of the region 200E and the portionR2 is the edge of the region 200E, the portion R3 suffers more lightleakage from other surrounding regions 200A˜200I than the portion R2.For example, the portion R3-1 could be affected by three surroundingregions 200B, 200C and 200F. The portion R2-1 could be affected by onesurrounding region 200B. Accordingly, the second compensation index C2is greater than the first compensation index C1. For example, the secondcompensation index C2 is triple of the first compensation index C1.Therefore, the CA for the portion R3 will be greater than the CA for theportion R2 in order to obtain an overall uniformity for the region 200E.

By utilizing the proposed layout modification method, the non-uniformitycould be compensated and improved without arranging another thin film toabsorb the light reflection and light leakage. Therefore, the efficiencyand throughput of the exposure manufacturing process will not besacrificed.

FIG. 3 is a schematic diagram illustrating the relationship between theuniformity of critical dimensions and the different steps ofcompensation, in accordance with some embodiments. The variety amountΔCD before compensation is 2 nm. As shown in FIG. 3, after the firstcompensation, the variety amount ΔCD is 1 nm. Afterwards, secondcompensation is executed after the first compensation, and the varietyamount ΔCD is decreased to be around 0.67 nm. If more compensations areexecuted, the variety amount ΔCD could be further decreased to 0.18 nmas shown in FIG. 3. Therefore, the variety amount ΔCD is effectivelycompensated for by the proposed layout modification method.

FIG. 4 is a flow chart illustrating the layout modification method of anexposure manufacturing process for fabricating an integrated circuit(IC), in accordance with some embodiments. In operation S402, theprocessor 1101 divides a patterned layer PL2 of a layout into a firstportion (the portion R1), a second portion (the portion R2) and a thirdportion (the portion R3) for an exposure manufacturing process toproduce a semiconductor device 200. In operation S404, the processor1101 retrieves an adjusting parameter, for example MEEF, for modifyingthe layout of the semiconductor device 200. In operation S406, theuniformity of critical dimension (CD) of the patterned layer PL2 ismeasured or simulated.

Afterwards, in operation S408, the processor 1101 determines acompensation amount (CA) based on the uniformity of CD and the adjustingparameter (i.e., MEEF). In operation S410, the processor 1101 determinesa first compensation index C1 and a second compensation index C2. Itshould be noted that the operations S404˜S410 could be executed at thesame time, or be executed in another sequence.

In operation S412, the processor 1101 adjusts the CD of the secondportion by utilizing the compensation amount multiplied by the firstcompensation index C1, and adjusts the CD of the third portion byutilizing the compensation amount multiplied by the second compensationindex C2. The detailed adjustment method in association with relatedparameters has been illustrated before, and would not be repeated again.Afterwards, in operation S414, a modified layout is generated tocompensate for the non-uniformity of the exposure manufacturing process.In some embodiment, the modified layout or a group of modified layoutsare used to fabricate mask for manufacturing the IC 130.

In some embodiments, one or more of the operations and/or functions ofthe tools and/or systems described with respect to FIGS. 1-4 is/areimplemented by specially configured hardware (e.g., by one or moreapplication-specific integrated circuits or ASIC(s)) which is/areincluded) separate from or in lieu of the processor 610. Someembodiments incorporate more than one of the described operations and/orfunctions in a single ASIC.

In some embodiments, the operations and/or functions are realized asfunctions of a program stored in a non-transitory computer readablerecording medium. Examples of a non-transitory computer readablerecording medium include, but are not limited to, external/removableand/or internal/built-in storage or memory unit, e.g., one or more of anoptical disk, such as a DVD, a magnetic disk, such as a hard disk, asemiconductor memory, such as a ROM, a RAM, a memory card, and the like.

By utilizing the proposed layout modification method, the non-uniformityduring the exposure manufacturing process could be compensated andimproved. Because arranging another thin film is not needed by theproposed layout modification method to absorb the light reflection andlight leakage, the efficiency and throughput of the exposuremanufacturing process will not be sacrificed.

In accordance with some embodiments, a layout modification method forfabricating a semiconductor device is provided. The layout modificationmethod includes calculating uniformity of critical dimensions of a firstportion and a second portion in a patterned layer by using a layout foran exposure manufacturing process to produce the semiconductor device. Awidth of the first and second portions equals a penumbra size of theexposure manufacturing process, and the penumbra size is utilized toindicate which area of the patterned layer is affected by light leakageexposure from another exposure manufacturing process. The layoutmodification method further includes compensating non-uniformity of thefirst and second portions of the patterned layer according to theuniformity of critical dimensions to generate a modified layout. Thefirst portion is divided into a plurality of first sub-portions and thesecond portion is divided into a plurality of second sub-portions in thepatterned layer. Each of the second sub-portions is surrounded by two ofthe first sub-portions.

In accordance with some embodiments, a layout modification method forfabricating a semiconductor device is provided. The layout modificationmethod includes dividing a patterned layer of a layout into a firstportion, a second portion and a third portion for an exposuremanufacturing process to produce the semiconductor device. A width ofthe second and third portions equals a penumbra size of the exposuremanufacturing process, and the penumbra size is utilized to indicatewhich area of the patterned layer is affected by light leakage exposurefrom another exposure manufacturing process. The layout modificationmethod further includes measuring uniformity of critical dimension ofthe patterned layer. The layout modification method further includesadjusting the critical dimension of the second and third portions of thepatterned layer according to the uniformity of critical dimension togenerate a modified layout. The patterned layer includes a plurality ofabsorbers, and a first width of the absorbers in the first portion isless than a second width of the absorbers in the second portion, and thesecond width of the absorbers is less than a third width of theabsorbers in the third portion.

In accordance with some embodiments, a non-transitory computer-readablemedium containing instructions which, when executed by a processor of acomputer system, cause the processor to execute a layout modificationmethod for fabricating a semiconductor device, is provided. Uniformityof critical dimension of a patterned layer is calculated with a layoutfor an exposure manufacturing process to produce the semiconductordevice. The patterned layer is divided into a first portion and a secondportion, and a width of the second portion equals a penumbra size of theexposure manufacturing process, wherein the penumbra size is utilized toindicate which area of the patterned layer is affected by light leakageexposure from another exposure manufacturing process. The criticaldimension of the second portion of the patterned layer is compensatedaccording to the uniformity of critical dimensions to generate amodified layout. The patterned layer includes a plurality of absorbers,and a first pitch of the absorbers in the first portion is greater thana second pitch of the absorbers in the second portion.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A layout modification method for fabricating asemiconductor device, comprising: calculating uniformity of criticaldimensions of a first portion and a second portion in a patterned layerby using a layout for an exposure manufacturing process to produce thesemiconductor device, wherein a width of the first and second portionsequals a penumbra size of the exposure manufacturing process, and thepenumbra size is utilized to indicate which area of the patterned layeris affected by light leakage exposure from another exposuremanufacturing process; and compensating non-uniformity of the first andsecond portions of the patterned layer according to the uniformity ofcritical dimensions to generate a modified layout, wherein the firstportion is divided into a plurality of first sub-portions and the secondportion is divided into a plurality of second sub-portions in thepatterned layer, wherein each of the second sub-portions is surroundedby two of the first sub-portions.
 2. The layout modification method asclaimed in claim 1, wherein compensating the non-uniformity of the firstand second portions of the patterned layer according to the uniformityof critical dimensions further comprises: obtaining an adjustingparameter for modifying the layout; determining a compensation amountbased on the adjusting parameter and the uniformity of the criticaldimensions; and compensating the critical dimension of the first portionof the patterned layer by utilizing the compensation amount.
 3. Thelayout modification method as claimed in claim 2, wherein the adjustingparameter is a Mask Error Enhancement Factor (MEEF) utilized for opticalproximity correction of the exposure manufacturing process of thesemiconductor device.
 4. The layout modification method as claimed inclaim 2, wherein the compensation amount is determined by dividing theuniformity of the critical dimension by the adjusting parameter.
 5. Thelayout modification method as claimed in claim 1, wherein the patternedlayer comprises a plurality of absorbers, and a first width of theabsorbers in the first portion is less than a second width of theabsorbers in the second portion.
 6. The layout modification method asclaimed in claim 1, wherein shape of the patterned layer is a polygon,and each of the first sub-portions is an edge area of the polygon andeach of the second sub-portions is a corner area of the polygon.
 7. Thelayout modification method as claimed in claim 1, further comprising:compensating non-uniformity between the first portion and a thirdportion of the patterned layer and non-uniformity between the second andthird portion of the patterned layer according to the uniformity ofcritical dimensions, so as to generate the modified layout, wherein thethird portion is surrounded by the first portion and the second portion.8. The layout modification method as claimed in claim 7, wherein thecritical dimension of the first portion of the patterned layer iscompensated by increasing a pattern width of the first portion ordecreasing a pattern pitch of the first portion according to a firstcompensation index for compensating the non-uniformity between the firstand third portions of the patterned layer, and a difference between afirst width of absorbers in the first portion and a second width ofabsorbers in the third portion is determined according to the firstcompensation index.
 9. The layout modification method as claimed inclaim 8, wherein the critical dimension of the second portion of thepatterned layer is compensated by increasing a pattern width of thesecond portion or decreasing a pattern pitch of the second portionaccording to a second compensation index for compensating thenon-uniformity between the second and third portions of the patternedlayer, and the second compensation index is greater than the firstcompensation index.
 10. A layout modification method for fabricating asemiconductor device, comprising: dividing a patterned layer of a layoutinto a first portion, a second portion and a third portion for anexposure manufacturing process to produce the semiconductor device,wherein a width of the second and third portions equals a penumbra sizeof the exposure manufacturing process, and the penumbra size is utilizedto indicate which area of the patterned layer is affected by lightleakage exposure from another exposure manufacturing process; measuringuniformity of critical dimension of the patterned layer; and adjustingthe critical dimension of the second and third portions of the patternedlayer according to the uniformity of critical dimension to generate amodified layout, wherein the patterned layer comprises a plurality ofabsorbers, and a first width of the absorbers in the first portion isless than a second width of the absorbers in the second portion, and thesecond width of the absorbers is less than a third width of theabsorbers in the third portion.
 11. The layout modification method asclaimed in claim 10, further comprising: determining a compensationamount based on the uniformity of critical dimension and an adjustingparameter for adjusting the critical dimension of the second portion ofthe patterned layer, wherein a first pitch of the absorbers in the firstportion is greater than a second pitch of the absorbers in the secondportion, and the second pitch of the absorbers is greater than a thirdpitch of the absorbers in the third portion.
 12. The layout modificationmethod as claimed in claim 11, wherein the adjusting parameter is a MaskError Enhancement Factor utilized for optical proximity correction of anexposure manufacturing process of the semiconductor device.
 13. Thelayout modification method as claimed in claim 11, wherein thecompensation amount is determined by dividing the uniformity of criticaldimension by the adjusting parameter.
 14. The layout modification methodas claimed in claim 10, wherein shape of the patterned layer is arectangle, the first portion is a central area of the rectangle, and thesecond portion is an edge area of the rectangle.
 15. The layoutmodification method as claimed in claim 14, wherein the third portion isa corner area of the rectangle.
 16. The layout modification method asclaimed in claim 10, wherein the critical dimension of the secondportion of the patterned layer is compensated by increasing a patternwidth of the second portion or decreasing a pattern pitch of the secondportion according to a first compensation index, and the criticaldimension of the third portion of the patterned layer is compensated byincreasing a pattern width of the third portion or decreasing a patternpitch of the third portion according to a second compensation index. 17.The layout modification method as claimed in claim 16, wherein thesecond compensation index is greater than the first compensation index.18. The layout modification method as claimed in claim 10, wherein thesecond portion is divided into a plurality of first sub-portions and thethird portion is divided into a plurality of second sub-portions in thepatterned layer, and the first portion is surrounded by the firstsub-portions and the second sub-portions.
 19. A non-transitorycomputer-readable medium containing instructions which, when executed bya processor of a computer system, cause the processor to execute alayout modification method for fabricating a semiconductor device,comprising: calculating uniformity of critical dimension of a patternedlayer with a layout for an exposure manufacturing process to produce thesemiconductor device, wherein the patterned layer is divided into afirst portion and a second portion, and a width of the second portionequals a penumbra size of the exposure manufacturing process, whereinthe penumbra size is utilized to indicate which area of the patternedlayer is affected by light leakage exposure from another exposuremanufacturing process; and compensating the critical dimension of thesecond portion of the patterned layer according to the uniformity ofcritical dimensions to generate a modified layout, wherein the patternedlayer comprises a plurality of absorbers, and a first pitch of theabsorbers in the first portion is greater than a second pitch of theabsorbers in the second portion.
 20. The non-transitorycomputer-readable medium as claimed in claim 19, wherein the criticaldimension of the second portion of the patterned layer is compensated byincreasing pattern width of the second portion or decreasing patternpitch of the second portion.